Clutch with lubricating device



Ap 1954 E. H. FLETCHER CLUTCH WITH LUBRICATING DEVICE 5 Sheets-Sheet 1 Filed NOV. 21, 1952 G INVENTOR EDWARD H. FLETCHER ATTORNEYS p l 27, 1954 ,E. H. FLETCHER CLUTCH WITH LUBRICATING DEVICE 3 Sheets-Sheet 2 iled Nov. 21, 1952 FIG. 2

INVENTOR EDWARD H. FLETCHER IZ CHANGE SPEED TRANSMISSION AT TORNEYS April 27, 1954 E. H. FLETCHER 2,676,686

CLUTCH WITH LUBRICATING DEVICE EDWARD H. FLETCHER Patented Apr. 27, 1954 v 2,676,686 CLUTCH WITH LUBRICATIN G DEVICE Edward H. Fletcher, Cedar Falls, Iowa, assignor to Deere Manufacturin corporation of Iowa 3' '00., Dubuque, Iowa, at

1 Application November 21, 1952, Serial No. 321,925

1 This inventionjrelates to driving mechanism and more particularly to clutch-controlling means therefor. Still more particularly the invention relates to a power take-01f driving mechanism for a vehicle such as an agricultural tractor. I

Heretofore, most agricultural tractors were equipped, either optionally or regularly, .with power take-01f shafts for driving implements used with the tractors. These shafts were normally gear-connected to the tractor transmission and as long as the tractor clutch was engaged, the associated implement parts would be driven. More recently, the industry .has experienced the development of a so-called continuous power. take-off shaft, differing from that heretofore known primarily because the power take-onshaft is direct-connected to the engine. In other'words, the newer power take-off shaft power train by-passes the transmission so, that disengagement of the engine clutch does not cause simultaneous cessation of operation of the power take-off shaft. Fundamentally, of course, the so-called continuous or "live power take-off shaft is not new. Nevertheless, there is considerable room for improvements in adapting the principle to modern agricultural tractors.

Inasmuch as the live power shaft is operative independently of the'engine clutch in the vehicle or tractor, it is desired that it be equipped with its own clutch. Because of the necessity for constant engagement and disengagement, this clutch must be particularly well designed tostand up imderlong usage. .It is-also important thatthe power trai'n'incorporate means for accommodating temporary or sustained-overloading so as -to prevent damage to the 'power train or vehicle. Accordingly, it is desired that a clutch of the friction type :be used in the power train to the power take-01f shaft. Other design characteristics peculiar to a power train of this type have been gained from long experience. According to the present invention, there are provided improvements in the arrangement and the association of the clutch with the power take-off parts.

The primary object of the invention is to provide an improved power take-off of the character referred to above, and particularly to improve the clutch means therein. One feature of the invention is the utilization .of yieldable means backing 4 6 Claims. (Cl. 192113) 2 up the clutch so that the clutch may yieldin response to temporary or sustained overloads. Another feature of the invention resides in means for efiiciently circulating oil through a multiple disk-type clutch. As to this phase of the invention, it is a feature to closely associate a circulating pump with the input shaft for the power take-off.

The foregoing and other important objects inherent in and encompassed by the invention will become apparent from the following detailed description and accompanying sheets of drawings, all pertaining to a preferred embodiment of the invention.

In the drawings:

Figure l is a side elevational view of a rear portion of a tractor, with the right-hand rear wheel omitted to expose the tractor body and associated power take-01f housing.

Figure 2 is a schematic plan view showing the power train from the tractor engine to the power take-off shaft.

Figure 3 is an enlarged fragmentary view as seen substantially along the line 3-3 of Figure 2.

Figure 4 is a still further enlarged transverse section as seen along the line 4-4 of Figure 2.

' Figure 5 is a longitudinal sectional view, on the s'caleof Figure 4, as seen along the line 5-5 of Figure 2. V

Figure 6 is a transverse fragmentary sectional view as seen along the line 6-6 of Figure 5.

The tractor illustrated in part in Figure 1 may be considered representative of a well-known typelof agriculturaltractor comprising a longitudinal body II) having its rear portion formed "of a final drive case or housing I2 of which the forward portion comprises a crankcase It for an internal combustion engine I6. Above the engine I6 is a fuel tank and hood structure I8 which is supported at its rear end in a standard 20 1oc ated somewhat conventionally ahead of an operators seat 22. A steering wheel 24 for the tractor front Wheels (not shown) is carried on a steering shaft. that is journaled in the upper portion of the standard 20. The operators seat 22 is located over a rear part of the final drive case I2, which case includes laterally outwardly extending axle housing portions 28 (only one of which is shownland in, which are respectively journaled rightand left-hand drive axles 30 and 32 (Figure 2). A traction wheel 34 is keyed to the left-hand axle 32 and a similar traction wheel (omitted from the drawings) is keyed to the right-hand axle 30.

The particular tractor shown is basically similar to that disclosed in the U. S. patent to McCray 1,957,221. In such tractor, the engine crankshaft, shown here at 36 in Figure 2, is transverse to the length of the tractor body l and has keyed to its left-hand end a conventional flywheel 38. The engine is of the twocylinder type in which the pistons reciprocate fore and aft. Connecting rods are shown schematically at 40 in Figure 2.

To the right-hand end of the crankshaft 36 is keyed a belt pulley $2 (Figures 1 and 2) and this belt pulley is associated in a manner not heretofore unknown with; an engine or main clutch designated generally by the numeral 44. In its simplest form, this clutch include the radial face of the belt pulley 42 as a clutch face" 46, a clutch plate as keyed to a sleeve jour-' naled on the crankshaft iit and a shiftable pressure plate 52 controlled inany suitable manner by a clutch control lever 55 (Figure l) A transmission input or driving gear 55 is keyed to or formed integrally with the clutch sleeve 48 and is in constant mesh with a transmission driven gear 53. This driven gear is keyed to a transmission input shaft 60, which enters the right-hand side of the final drive or transmission case and delivers input power to a change speed gear set of any conventional type. This transmission mechanism has been illustrated only schematically (Fig. 2) since the details thereof form no part of the present invention.

As long as the main or engine clutch id is disengaged, as shown in Figure 2, the crankshaft rotates without transmitting any power to the transmission mechanism in the final drive case It. Accordingly, there will be no forward progress of the tractor, since the drive axles 3H and 32 do not receive power from the engine. However, when sion input gear 55 is driven through the clutch and transmits power to the transmission via the transmission driven gear 58 and input shaft 60. Selection of a suitable gear combination in the transmission Will, of course, cause the engine 16 to drive the. axles and 32.

A power take-off input gear 82 is keyed to the right-hand end portion'of the crankshaft 3S and lies closely alongside the transmission driving .or input gear 55. The power take-off gear 62 is in constant mesh with a power take-off driven gear 64'. that is journaled on the transmission input shaft Eiil closely alongside the transmission driven gear 58. The gears 52 and "54 are driven at all times as long as the crankshaft 36 rotating, irrespective of whether or not the main clutch 44 is engaged.

A sliding pinion 515, constrained for rotation with but axially shiftable on a power take-off transfer shaft 68 may be selectively engaged with or disengaged from the power take-off driven gear 65. The shaft 68' has keyed theretoa bevel pinion it which is in constant mesh with a bevel pinion i2 keyed to a longitudinally running power take-off transfer shaft, M. The shaft 14 has its terminal end connected by means of a clutch, designated for the present by the numeral 56, to the ultimate power take-off shaft 18. The details of this arrangement will be described below As shown in Figure 4, thetransmiss'ionor final the clutch isengaged, the transmisdrive casing 12 has a bottom or floor and a right-hand upright side wall 82. This wall is provided at a lower portion thereof with a suitable antifriction bearing 84 for journaling one end portion of the transverse shaft '68. The inner end of the shaft is journaled in a bearing 86 in an integral upstanding portion of the casing floor 80. The right-hand end of the shaft (left-hand end as viewed in Figure 4) extends outwardly of the wall 82 and is splined at 88 to slidably carry the gear 66 thereon. The gear 68 and the gears 58-, 64, 56 and 62 arev enclosed at-the righthand side of the tractor by an auxiliary casing 88.

The hub of the gear 66 is provided, as is generally conventional, with an annular collar 90 with which a shifter fork 92 is cooperative. This fork is carried at one end of a shifter shaft 9i which-extends through the casing wall 82 to a controllable connection with an arm 6 at the lower end of a shifter control rod 98. lhis rod projects upwardly through the top of the casing and has a handle I09 (Figure 1) by means of which the operator may readily engage or disengage the pinion 5B and gear 6 In normal operation-that is, when the tractor is used with an implement to be driven by the power take-off shaft l8--the pinion 65:3 will be in constant mesh with the driven gear 64. In those cases in which the tractor is used alone or with an implement having no driven parts, the pinion 56 may be disengaged to save wear on the power take-off shaft and the parts that make up its power-transmitting train.

The power take-off unit itself may be considered an attachment, since it may be furnished with the tractor as regular equipment or as optional, equipment. In. any event, the clutch 76, previously described in connection withv the schematio illustration in Figure2, is. enclosed in a power take-off casing or housing designated generally bythe numeral I82. This housing has a front wall H14 through which the rear end of the longitudinal power take-off transfer shaft i i extends. Insofar as concerns the final part of the power train between the shaft M and the shaft 18, the shaft 14 may be considered a driving shaft.

The driving shaft 14 is flanged at let at its rear end and is rigidly secured to the radial portion of arearwardly facing coaxial cupor bell-shaped member 108. The portion'of the shaft M a jacent the member I98 is appropriately journaled in a bearing He in a'sleeve portion N2 of the casing m2 which spaces the wall I64 of the casing I92 forwardly from a second wall 5 i i. The clutch I5 is located rearwardly of the second wall 114 and is of the multiple-disk type comprising a plurality of alternating driving and driven disks H5 and H8. The driving disks lie are keyed at their outer peripheries to the cylindrical portion of the bell-shaped memberlllli'. The driven disks H8 are keyed at their inside diameters to a driven shaft 1'26 that is coaxial with the driving shaft 14. The rear end of the driving shaft M is recessed and provided with a pilot bearing I22 in'which is journaled the forward reduced end of the driven shaft I20.

The rear end of the driven shaft i2i is appropriately journaled at 124 in a bearing in a rear wall 126 of the casing I02. A driving pinion i222 is keyed tothat portion of the driven shaft just forwardly of the bearing 12.4; This gear or pinion is in constantniesh with a power take-off shaftoutputrgear I38"; Thegear [Bil is keyed: to

second diameter portion the inner end of the power take-off shaft 18, the shaft 18 extending rearwardly through the rear wall I26 of the casing I02 for ready access to connection with implements used with the tractor.

The clutch 16 is engaged by means of com pressing the disks H6 and H8 between a pair of clutch plates I32 and I34. These plates or members are slidable on the driven shaft I by means of the splines that form the keyed connections with the driven disks H8. The forward member I 32 is held against forward displacement by a snap ring I36. The rearward member may be considered an operating member and is under control of an actuator device designated generally by the numeral I38. The clutch includes springs I40 (only one of which is shown), which comprise first biasing means for normally spreading the members I32 and I34 so that the clutch is normally disengaged. The pinion I28 that is keyed to the rear end portion of the driven shaft I20 serves as abutment means between which and the operating member I34 the actuator de-.

vice I38 functions. The actuator device comprises a reaction member I'42-keyed to and axially slidable on the splined driven shaft I20. This reaction member. is capable of being spring-loaded by second biasing means comprising a plurality of compression springs I44, so that the bias is to the right as seen in Figure 5, or in a direction tending to compress the disks in the clutch 16. The springs I44 seat against an annular member in the form of a washer I46 which in turn abuts the front face of the gear or pinion I28. Each of the springs I44 is received in a bore I48 having its axis parallel to the axis of the driven shaft I20 and the forward ends of the springs seat respectively in the front ends of the bores I48. From this. it will be seen that the reaction member I 42 is recessed at its rear to receive the springs I44; and it has a front face I50 which forms one of a pair of cooperative cam surfaces for exert- 'ing thrust on the clutch 16 to compress the disks I I6 and H8. A second member I52 is slidably keyed'on the splined driven shaft I20 and is interposed between the cam face I50 of the reaction member I42 and the rear or left-hand face of the operating member I34. The member I52 is made up of several parts but the details are not important here. Therefore, it willbe considered as being a single member; The rear face of the member I 52 provides the second of the cooperate ing'cam surfaces, designated by thenumeral I54.

A plurality of balls I56 (only one of which; is shown) is cooperative between the cam faces I 50 and I54 for spreading the members I42 and I52 axially apart to compress the disks in the clutch 16. The position of the balls is determinedby-a control ring I58 that encircles the reaction mem-i} The: control ring I58 is slidable on but constrained for rotation with the reactionmembenlfl by means;

ber I42 and its component member I52.

of a pin I60 that operates in a keyway I62 in the reaction member I42. g j, V. c

The ring I58 has in effect two inside diameters of different sizes. The first diameter portion, designated by the numeral I64,'is smaller than'a I66. Consequently, when the control ring I58 is moved to its forward position as shown in Figure 5, the balls I56 are forced between the cam faces I54 and I54 and are maintained in that position as long as the control ring is in its forward position. Since the diameter of each of the balls is greater than the axial distance between the members I '42 and I 52 ,-:the members-are spread axially andthe clutch disks I I6 and II 8 are compressed against the first biasing means or clutch springs I40. This results because the second biasing means, comprising the compression springs I44, is materially stronger than the springs I40, and when the clutch is fully engaged, the springs I44 are not fully compressed. Consequently, the clutch is not backed up positively but is backed up yieldingly by the springs I44. Therefore, should a temporary or sustained overload occur on the power take-01f shaft 18, the springs I44 can yield sufficiently to permit the disks H6 and H8 to slip. Such slipping will, of course, prevent damage to the other parts of the power train.

When the control ring I58 is moved in the opposite'direction (to the left as viewed in Figure 5), the ball are released because of the increased diameter of the diameter portion I66. That is to say, the balls escape from the limited space between the cam faces I56 and I54 on the members I42 and I52, and these members move toward each other to relax the pressure on the clutch disks;

The actuator device I38 and its control ring I58 thus comprise bipositional control means acting on the operating member I34 and effective in one position to exert thrusting force in opposite directions for spreading the members I42 and I34 axially apart against their respective biasing means I44 and I 42 to engage the clutch and effective in a second position to relieve the members of the thrust forces so that the members may be returned by their respective biasing meansxto their neutral or normal position in which the clutch 16 is disengaged.

The control ring I 58 is actuated between its two positions by a control fork I68, of conventional construction, that engages an annular external groove I10 in the ring I58. The control fork I68 is keyed to a short transverse rock-shaft I12 that extends exteriorly at the right-hand side of the power take oif casing I02 for connection to a forwardly extending arm I14. The forward end of this arm is connected by an actuating link I 16 to a control lever I18 pivoted at I within easy reach of an operator on the operator seat 22. The control fork further includes interiorly of the casing I62 a, forwardly extending short arm I 62 which abuts an adjustable screw I84 carried by the top wall of the casing I02. When the arm I82 engages the internal end of the screw I 84, the maximum or engaged position of the control ring I58 is determined.

When the control ring is moved in the opposite direction, the opposing pressures of the two sets of compression springs I40 and I44, plus centrifugal force, compel the balls I56 outwardly to be confined by the larger diameter portion I66 of the ring. The balls in this position serve as detents to prevent accidental movement of the ring I58 to itsclutch-engaged position; although, these 'fdetentskmay be easily overcome by pressure exlcrted by the operator on the control lever I18. The'clutch 16 is disengaged by downward pressure applied to the operating lever I18.

The details of the actuator device I38 are not broadly new and actuator of this type are known in various forms. The actuator shown differs prijmarily in that it is backed up by the yieldable meansor springs I44 instead of acting against a fixed abutment. In the case of fixed abutment, wear in the clutch plates ultimately results in slippage of the clutch. The springs I44 are, of course, calculated to prevent slippage during normal conditions. and. expand a the clutch plates auras-so wear, eliminating the need for frequent adjustment. At the same time, the pressure of the springs I44 in the clutch' may be relatively light so as to enable the clutch to slipunder excessive loads, whereas the yieldably backed up reaction member such as at I42 servesto maintain engageient of the clutch 16 during normal operation but permits slippage dueto overload.

The springs I44 servean additional function, not heretofore known in prior actuator devices. As will be seen in Figure 5, in which figure the clutch I is engaged, the reaction member I42 has fixed thereto a flanged ring I85 which, aswil-l be hereinafter apparent, serves as a combined stop and brake element or portion. There is. fixed to the-rear wall 26 of the power take-off casing. I02 a second cooperative stop or brake element or portion in the form of a ring I88 having its opposite radial faces provided respectively with brake material laid and I92. Whenthe clutch is engaged, as shown in Figure 5, the front radial face of the reaction member ring 5536 is spaced rearwardly from the rear brake face I90 on the ring. I88. When the control ring i523 is moved rearwardlyto disengage the clutch, pressure on the balls I56; is released and, as stated above, the balls are free to escape from between the cam faces 15!] and I54 into the confinement of the ring portion I68 of the ring I58. The springs I44 then urge the reaction member E 52 forwardly but the forward movement thereof is limited because of engagement of the ring I86 with the brake face 85. Thus, cooperation between the parts 535 and iiif! serves not only to limit forward movement of the actuator memher 442 but retards the speed of rotation thereof, since the ring 588 is fixed to the reaction member M2 and the ring I33 is fixed to the housing or casing "it, as by a plurality of. cap screws I34 (only one of which is shown).

in addition to the braking effect accomplished by the parts just described, a secondary brake may be resorted to by manual pressure downwardly on the clutch control lever H8. The rear face of the control ring 558 has a-radial brake surface I96 that is normally axially spaced from the opposed brake face E92 on the ring I88. If the brake as applied at Hit-46B is insufficient to retard the speed of rotation of the power take-off shaft I8 and whatever is connected to it, the ring, I58 may be forced rearwardly under control. of the operator so that the second brake is applied at I 96- I92. The two brakes in combination adequately accomplish effecting braking for most extreme operat ing conditions. The braking effectiveness at ace-49s accommodates normal operation.

In addition to the foregoing, the invention includes another feature that pertains to the circulation of lubricant through the multiple disk clutch "It. Theinterior of the casing I02 forms a compartment adapted to contain lubricant to substantially the level indicated by the line designated L in Figure 5. The facings on the clutch disks H8 and H8 are, of course, the kind adapted to operate in alubricant bath.

The sleeve portion II2 of the housing I02, previously described, encircles the rear end portion of the driven shaft 14 just ahead of the bearing H0. The inner portion of the sleeve is enlarged so that a cavity I98 is formed about the shaft. This cavity is sealed at one end by the bearing H8 and at its other end by the outside diameter of the shaft H4 as designated generally by the numeral 29G. Just ahead of the portion 2-00, the shaft I4 is splined at 202 toiserve asa pumpge'ar.

The splines are of limitedaxiali extent and termi 82. nate sacs to" leave. a. cylindrical outside diameter. 204, ahead of which the shaft I4 is reduced at8206- to accommodate a pair of lubricant seals 20 The lubricant seals 2Il8are established between the reduced. portion 206 of the driving shaft I4 and an auxiliary housing 2Il] rigidly secured to the front face of the wall I04 of the casing I02. This wall forms a pump chamber 2I2 that encloses the pump gear or spline 202 and a pump idler. gear 2I4. The formation of the-pump gear 202 as a spline on the driving shaft I4 instead of as a separate gear permits the use of a smaller gear and cuts down the amount of space needed for the pump.

The pump chamber M2 is connected by a suction passage M6. to the lubricant sump provided at. the lower portion of the clutch compartment. The. suction passage enters the pump housing 2H! and leads. toa pump inlet 229. The outlet 222. of the pump is connected by a short passage 224 to the cavity I98 in the housing sleeve H2. The discharge end of. the high-pressure passage 224 within the cavity I98 is visible at 225 in Figure5.

The rear or terminal end of the driving shaft I4- has an axial bore or passage 228 therein. The inner or forward end of this bore or passage communicates with the cavity I.98 via one or more radial passage portions 230, so that the inlet end of the bore 228 isin. axially spaced relation to the clutch compartment. The rear or terminal end of the passage communicates across the pilot bearing I22 with an. axial. bore or passage 232 formed in the proximate end portion of the driven shaft. I20. Axially offset radial passages 234 in the driven shaftI20 communicate the axial passage 232 with theinterior of the clutch It. Since theoutside of the driven shaft I20 is longitudinal- 1y splined, as explained before, the passages 234 are in flu-id transfer relationship with the clutch disks H6 and. H8. Accordingly, the pump 2:??- 2 I 4 circulates lubricant by drawing lubricant from the sump in the clutch compartment through the suction passage 2 I6-2 I8 and recirculates it through the high-pressure passage Mil-22% and shaft passages 230, 228, 232, and 23 3 to the interior of the clutch.

The relationship of the pump to the clutch is one of compact organization. and, although the two are closely related, they are separated by the housing portions so that either the clutch or the pump may be serviced without disturbing the other. 7

Various features of the invention in this respect and in other respects will, although not expressly enumerated herein, undoubtedly occur to those versed in the art, as likewise will many modifications and alterations in the preferred design illustrated, all. of which'may'be achieved without departing from. the spirit and scope of the appended claims.

What is claimed is:

1. Driving mechanism, comprising: a rotatable driving shaft having a terminal end; a driven shaft coaxial with the driving shaft and having a terminal end proximate to the terminal end of the driving shaft; bearing means journalling one shaft end on the other; amultiple-disk clutch c0- axial with the shafts and having driving driven disks keyed respectively to the shafts; the driven shaft having radial passage means therein'opening to the clutch disks'and an axial passage communicating with: theradial means and opening at the terminal end of the driven shaft; the driving shaft having an axial passage therein opening at the terminal end of the driving shaft in communication with the driven shaft axial passage and extending into the driving shaft to an inlet opening spaced axially from the clutch; and exposed to the exterior of said driving shaft; housing means providing a compartment containing the clutch and at least the terminal ends of the shafts and adapted to contain lubricant at a predetermined level; a housing portion providing a pump chamber supported by the housing means and having a suction passage communicating with the compartment below the lubricant level and a high-pressure passage leading to the inlet opening in the driving shaft; and a lubricant pump in the pump chamber and driven by the driving shaft for drawing lubricant from the compartment through the suction passage and circulating such lubricant through the high-pressure passage and the shaft and passages and. through the clutch disks for return to the compartment.

2. The invention defined in claim 1, in which: the pump is a gear pump comprising a first gear forming a circumferentially splined portion within the outside diameter of the driving shaft and a second gear mehing with the splined portion.

3. Driving mechanism, comprising: a rotatable driving shaft having a terminal end; a driven shaft coaxial with the driving shaft and having a terminal end proximate to the terminal end of the driving shaft; bearing means journalling one shaft end on the other; a multiple-disk clutch coaxial with the shafts and having driving and driven disks keyed respectively to the shafts; the driven shaft having radial passage means therein opening to the clutch disks and an axial passage communicating with the radial passage means and opening at the terminal end of the driven shaft; the driving shaft having an axial passage therein opening at the terminal end of the driving shaft in communication with the driven shaft axial passage and extending into the driving shaft to a radial inlet passage opening to the circumference of the driving shaft in axially spaced relation to the clutch; housing means providing a compartment containing the clutch and at least the terminal ends of the shafts and adapted to contain lubricant at a predetermined level; said housing means including a cavity with which said radial inlet passage communicates; a housing portion providing a pump chamber supported by the housing means and having a suction passage communicating .1.

with the compartment below the lubricant level and a high-pressure passage leading to the cavity; and a lubricant pump in the pump chamber and driven by the driving shaft for drawing lubricant from the compartment through the suction passage and circulating such lubricant through the high-pressure passage; the cavity and the shaft passages, and through the clutch for return to the compartment.

4. Driving mechanism, comprising: a rotatable driving shaft having a terminal end; a driven shaft coaxial with the driving shaft and having a terminal end proximate to the terminal end of the driving shaft; bearing means journalling one shaft end on the other; a multiple-disk clutch coaxial with the shafts and having driving and driven disks keyed respectively to the shafts; the driven shaft having radial passage means therein opening to the clutch disks and an axial passage communicating with the radial passage means and opening at the terminal end of the driven shaft; the driving shaft having an axial passage therein opening at the terminal end of the driving shaft in communication with the driven shaft axial passage and extending into the driving shaft to an inlet opening spaced axially from the clutch and exposed to the exterior of said driving shaft; a lubricant sump opening to the clutch; a lubricant pump driven by the driving shaft and including a suction conduit to the sump and a high-pressure passage to the driving shaft inlet opening.

5. Driving mechanism, comprising: a housing having an upright wall and'a bottom providing an internal lubricant compartment; a driving shaft journaled by the housing and extending through the wall to have an internal end within the compartment and an external portion outside the compartment, said shaft having passage means therein including an inlet opening outside the compartment and an outlet opening at said internal end; a driven shaft journaled in the housing coaxially with the driving shaft and having one end proximate to the internal end of the driving shaft, said driven shaft having an axial passage means therein including an inlet opening at its driving-shaft-proximate end in fluid transfer communication with the driving shaft outlet and further including a radial outlet opening through the circumference of said driven shaft within the compartment; clutch means within the compartment and including selective engageable and disengageable clutch elements coaxial with and connected respectively to the shafts and arranged so that certain of said elements are exposed in fluid-receiving relationship to the radial outlet in the driven shaft; means outside the compartment providing a pump chamber surrounding the external portions of the driving shaft and having a suction passage leading through the housing wall to a lower part of the compartment and a high-pressure passage leading to the driving shaft inlet; and a lubricant pump in the chamber and driven by the driving shaft for drawing lubricant from the compartment via the suction passage and for circulating such lubricant through the shaft passage means to the clutch.

6. Driving mechanism, comprising: a housing having an upright wall and a bottom providing an internal lubricant compartment; a driving shaft journaled by the housing and extending through the wall to have an internal end within the compartment and an external portion outside the compartment, said shaft having passage means therein including an inlet opening radially to the circumference of the shaft outside the compartment and an outlet opening axially at the internal end of the shaft; means on the housing outside the compartment and embracing the external portion of the shaft and providing a cavity surrounding the radial inlet and a pump chamber axially separate from the cavity and surrounding said external portion of the shaft; a driven shaft journaled in the housing coaxially with the driving shaft and having one end proximate to the internal end of the driving shaft, said driven shaft having an axial passage means therein including an inlet opening at its drivingshaft-proximate end in fluid-transfer communication with the driving shaft outlet and further including a radial outlet opening through the circumference of said driven shaft within the compartment; clutch means within the compartment and including selective engageable and disengageable clutch elements coaxial with and connected respectively to the shafts andarranged so that'certain of said elements are exposed in fluid-receiving relationship to the radial outlet in the driven shaft; means providing a suction passage from the compartment to the pump chamber; means providing a high-pressure passage leading from the pump chamber to the aforesaid cavity; and a lubricant pump in the pump chamber and driven by the driving shaft for drawing lubricant from the compartment via the suction passage and for circulating such lubricant through the cavity and. shaft pasage means to the clutch.

References "Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Hoffman Feb. 12, 1929 Pierson Sept. 26, 1933 Hobbs Feb. 21, 1950 McDowell et al. Sept. 5, 1950 FOREIGN PATENTS Country Date Great Britain Aug. 17, .1927 

